fscache: convert object to use workqueue instead of slow-work (8b8edefa) · Commits · 戴 / test

Documentation/filesystems/caching/fscache.txt

+5 −5

fs/cachefiles/namei.c

+6 −7

Original line number	Original line	Diff line number	Diff line
	@@ -37,9 +37,9 @@ void __cachefiles_printk_object(struct cachefiles_object *object,

	printk(KERN_ERR "%sobject: OBJ%x\n",		printk(KERN_ERR "%sobject: OBJ%x\n",
	prefix, object->fscache.debug_id);		prefix, object->fscache.debug_id);
	printk(KERN_ERR "%sobjstate=%s fl=%lx swfl=%lx ev=%lx[%lx]\n",		printk(KERN_ERR "%sobjstate=%s fl=%lx wbusy=%x ev=%lx[%lx]\n",
	prefix, fscache_object_states[object->fscache.state],		prefix, fscache_object_states[object->fscache.state],
	object->fscache.flags, object->fscache.work.flags,		object->fscache.flags, work_busy(&object->fscache.work),
	object->fscache.events,		object->fscache.events,
	object->fscache.event_mask & FSCACHE_OBJECT_EVENTS_MASK);		object->fscache.event_mask & FSCACHE_OBJECT_EVENTS_MASK);
	printk(KERN_ERR "%sops=%u inp=%u exc=%u\n",		printk(KERN_ERR "%sops=%u inp=%u exc=%u\n",
	@@ -212,7 +212,7 @@ wait_for_old_object:

	/* if the object we're waiting for is queued for processing,		/* if the object we're waiting for is queued for processing,
	* then just put ourselves on the queue behind it */		* then just put ourselves on the queue behind it */
	if (slow_work_is_queued(&xobject->fscache.work)) {		if (work_pending(&xobject->fscache.work)) {
	_debug("queue OBJ%x behind OBJ%x immediately",		_debug("queue OBJ%x behind OBJ%x immediately",
	object->fscache.debug_id,		object->fscache.debug_id,
	xobject->fscache.debug_id);		xobject->fscache.debug_id);
	@@ -220,8 +220,7 @@ wait_for_old_object:
	}		}

	/* otherwise we sleep until either the object we're waiting for		/* otherwise we sleep until either the object we're waiting for
	* is done, or the slow-work facility wants the thread back to		* is done, or the fscache_object is congested */
	* do other work */
	wq = bit_waitqueue(&xobject->flags, CACHEFILES_OBJECT_ACTIVE);		wq = bit_waitqueue(&xobject->flags, CACHEFILES_OBJECT_ACTIVE);
	init_wait(&wait);		init_wait(&wait);
	requeue = false;		requeue = false;
	@@ -229,8 +228,8 @@ wait_for_old_object:
	prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);		prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
	if (!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags))		if (!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags))
	break;		break;
	requeue = slow_work_sleep_till_thread_needed(
	&object->fscache.work, &timeout);		requeue = fscache_object_sleep_till_congested(&timeout);
	} while (timeout > 0 && !requeue);		} while (timeout > 0 && !requeue);
	finish_wait(wq, &wait);		finish_wait(wq, &wait);

fs/fscache/internal.h

+7 −0

Original line number	Original line	Diff line number	Diff line
	@@ -82,6 +82,13 @@ extern unsigned fscache_defer_lookup;
	extern unsigned fscache_defer_create;		extern unsigned fscache_defer_create;
	extern unsigned fscache_debug;		extern unsigned fscache_debug;
	extern struct kobject *fscache_root;		extern struct kobject *fscache_root;
			extern struct workqueue_struct *fscache_object_wq;
			DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);

			static inline bool fscache_object_congested(void)
			{
			return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
			}

	extern int fscache_wait_bit(void *);		extern int fscache_wait_bit(void *);
	extern int fscache_wait_bit_interruptible(void *);		extern int fscache_wait_bit_interruptible(void *);

fs/fscache/main.c

+76 −0

Original line number	Original line	Diff line number	Diff line
	@@ -15,6 +15,7 @@
	#include <linux/sched.h>		#include <linux/sched.h>
	#include <linux/completion.h>		#include <linux/completion.h>
	#include <linux/slab.h>		#include <linux/slab.h>
			#include <linux/seq_file.h>
	#include "internal.h"		#include "internal.h"

	MODULE_DESCRIPTION("FS Cache Manager");		MODULE_DESCRIPTION("FS Cache Manager");
	@@ -40,22 +41,89 @@ MODULE_PARM_DESC(fscache_debug,
	"FS-Cache debugging mask");		"FS-Cache debugging mask");

	struct kobject *fscache_root;		struct kobject *fscache_root;
			struct workqueue_struct *fscache_object_wq;

			DEFINE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);

			/* these values serve as lower bounds, will be adjusted in fscache_init() */
			static unsigned fscache_object_max_active = 4;

			#ifdef CONFIG_SYSCTL
			static struct ctl_table_header *fscache_sysctl_header;

			static int fscache_max_active_sysctl(struct ctl_table *table, int write,
			void __user *buffer,
			size_t lenp, loff_t ppos)
			{
			struct workqueue_struct **wqp = table->extra1;
			unsigned int *datap = table->data;
			int ret;

			ret = proc_dointvec(table, write, buffer, lenp, ppos);
			if (ret == 0)
			workqueue_set_max_active(wqp, datap);
			return ret;
			}

			ctl_table fscache_sysctls[] = {
			{
			.procname = "object_max_active",
			.data = &fscache_object_max_active,
			.maxlen = sizeof(unsigned),
			.mode = 0644,
			.proc_handler = fscache_max_active_sysctl,
			.extra1 = &fscache_object_wq,
			},
			{}
			};

			ctl_table fscache_sysctls_root[] = {
			{
			.procname = "fscache",
			.mode = 0555,
			.child = fscache_sysctls,
			},
			{}
			};
			#endif

	/*		/*
	* initialise the fs caching module		* initialise the fs caching module
	*/		*/
	static int __init fscache_init(void)		static int __init fscache_init(void)
	{		{
			unsigned int nr_cpus = num_possible_cpus();
			unsigned int cpu;
	int ret;		int ret;

	ret = slow_work_register_user(THIS_MODULE);		ret = slow_work_register_user(THIS_MODULE);
	if (ret < 0)		if (ret < 0)
	goto error_slow_work;		goto error_slow_work;

			fscache_object_max_active =
			clamp_val(nr_cpus,
			fscache_object_max_active, WQ_UNBOUND_MAX_ACTIVE);

			ret = -ENOMEM;
			fscache_object_wq = alloc_workqueue("fscache_object", WQ_UNBOUND,
			fscache_object_max_active);
			if (!fscache_object_wq)
			goto error_object_wq;

			for_each_possible_cpu(cpu)
			init_waitqueue_head(&per_cpu(fscache_object_cong_wait, cpu));

	ret = fscache_proc_init();		ret = fscache_proc_init();
	if (ret < 0)		if (ret < 0)
	goto error_proc;		goto error_proc;

			#ifdef CONFIG_SYSCTL
			ret = -ENOMEM;
			fscache_sysctl_header = register_sysctl_table(fscache_sysctls_root);
			if (!fscache_sysctl_header)
			goto error_sysctl;
			#endif

	fscache_cookie_jar = kmem_cache_create("fscache_cookie_jar",		fscache_cookie_jar = kmem_cache_create("fscache_cookie_jar",
	sizeof(struct fscache_cookie),		sizeof(struct fscache_cookie),
	0,		0,
	@@ -78,8 +146,14 @@ static int __init fscache_init(void)
	error_kobj:		error_kobj:
	kmem_cache_destroy(fscache_cookie_jar);		kmem_cache_destroy(fscache_cookie_jar);
	error_cookie_jar:		error_cookie_jar:
			#ifdef CONFIG_SYSCTL
			unregister_sysctl_table(fscache_sysctl_header);
			error_sysctl:
			#endif
	fscache_proc_cleanup();		fscache_proc_cleanup();
	error_proc:		error_proc:
			destroy_workqueue(fscache_object_wq);
			error_object_wq:
	slow_work_unregister_user(THIS_MODULE);		slow_work_unregister_user(THIS_MODULE);
	error_slow_work:		error_slow_work:
	return ret;		return ret;
	@@ -96,7 +170,9 @@ static void __exit fscache_exit(void)

	kobject_put(fscache_root);		kobject_put(fscache_root);
	kmem_cache_destroy(fscache_cookie_jar);		kmem_cache_destroy(fscache_cookie_jar);
			unregister_sysctl_table(fscache_sysctl_header);
	fscache_proc_cleanup();		fscache_proc_cleanup();
			destroy_workqueue(fscache_object_wq);
	slow_work_unregister_user(THIS_MODULE);		slow_work_unregister_user(THIS_MODULE);
	printk(KERN_NOTICE "FS-Cache: Unloaded\n");		printk(KERN_NOTICE "FS-Cache: Unloaded\n");
	}		}

fs/fscache/object-list.c

+5 −6

Original line number	Original line	Diff line number	Diff line
	@@ -34,8 +34,8 @@ struct fscache_objlist_data {
	#define FSCACHE_OBJLIST_CONFIG_NOREADS 0x00000200 /* show objects without active reads */		#define FSCACHE_OBJLIST_CONFIG_NOREADS 0x00000200 /* show objects without active reads */
	#define FSCACHE_OBJLIST_CONFIG_EVENTS 0x00000400 /* show objects with events */		#define FSCACHE_OBJLIST_CONFIG_EVENTS 0x00000400 /* show objects with events */
	#define FSCACHE_OBJLIST_CONFIG_NOEVENTS 0x00000800 /* show objects without no events */		#define FSCACHE_OBJLIST_CONFIG_NOEVENTS 0x00000800 /* show objects without no events */
	#define FSCACHE_OBJLIST_CONFIG_WORK 0x00001000 /* show objects with slow work */		#define FSCACHE_OBJLIST_CONFIG_WORK 0x00001000 /* show objects with work */
	#define FSCACHE_OBJLIST_CONFIG_NOWORK 0x00002000 /* show objects without slow work */		#define FSCACHE_OBJLIST_CONFIG_NOWORK 0x00002000 /* show objects without work */

	u8 buf[512]; /* key and aux data buffer */		u8 buf[512]; /* key and aux data buffer */
	};		};
	@@ -231,12 +231,11 @@ static int fscache_objlist_show(struct seq_file m, void v)
	READS, NOREADS);		READS, NOREADS);
	FILTER(obj->events & obj->event_mask,		FILTER(obj->events & obj->event_mask,
	EVENTS, NOEVENTS);		EVENTS, NOEVENTS);
	FILTER(obj->work.flags & ~(1UL << SLOW_WORK_VERY_SLOW),		FILTER(work_busy(&obj->work), WORK, NOWORK);
	WORK, NOWORK);
	}		}

	seq_printf(m,		seq_printf(m,
	"%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %1lx %1lx \| ",		"%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %1lx %1x \| ",
	obj->debug_id,		obj->debug_id,
	obj->parent ? obj->parent->debug_id : -1,		obj->parent ? obj->parent->debug_id : -1,
	fscache_object_states_short[obj->state],		fscache_object_states_short[obj->state],
	@@ -249,7 +248,7 @@ static int fscache_objlist_show(struct seq_file m, void v)
	obj->event_mask & FSCACHE_OBJECT_EVENTS_MASK,		obj->event_mask & FSCACHE_OBJECT_EVENTS_MASK,
	obj->events,		obj->events,
	obj->flags,		obj->flags,
	obj->work.flags);		work_busy(&obj->work));

	no_cookie = true;		no_cookie = true;
	keylen = auxlen = 0;		keylen = auxlen = 0;

Original line number	Original line	Diff line number	Diff line
	@@ -343,8 +343,8 @@ This will look something like:
	[root@andromeda ~]# head /proc/fs/fscache/objects		[root@andromeda ~]# head /proc/fs/fscache/objects
	OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS EM EV F S \| NETFS_COOKIE_DEF TY FL NETFS_DATA OBJECT_KEY, AUX_DATA		OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS EM EV F S \| NETFS_COOKIE_DEF TY FL NETFS_DATA OBJECT_KEY, AUX_DATA
	======== ======== ==== ===== === === === == ===== == == = = \| ================ == == ================ ================		======== ======== ==== ===== === === === == ===== == == = = \| ================ == == ================ ================
	17e4b 2 ACTV 0 0 0 0 0 0 7b 4 0 8 \| NFS.fh DT 0 ffff88001dd82820 010006017edcf8bbc93b43298fdfbe71e50b57b13a172c0117f38472, e567634700000000000000000000000063f2404a000000000000000000000000c9030000000000000000000063f2404a		17e4b 2 ACTV 0 0 0 0 0 0 7b 4 0 0 \| NFS.fh DT 0 ffff88001dd82820 010006017edcf8bbc93b43298fdfbe71e50b57b13a172c0117f38472, e567634700000000000000000000000063f2404a000000000000000000000000c9030000000000000000000063f2404a
	1693a 2 ACTV 0 0 0 0 0 0 7b 4 0 8 \| NFS.fh DT 0 ffff88002db23380 010006017edcf8bbc93b43298fdfbe71e50b57b1e0162c01a2df0ea6, 420ebc4a000000000000000000000000420ebc4a0000000000000000000000000e1801000000000000000000420ebc4a		1693a 2 ACTV 0 0 0 0 0 0 7b 4 0 0 \| NFS.fh DT 0 ffff88002db23380 010006017edcf8bbc93b43298fdfbe71e50b57b1e0162c01a2df0ea6, 420ebc4a000000000000000000000000420ebc4a0000000000000000000000000e1801000000000000000000420ebc4a

	where the first set of columns before the '\|' describe the object:		where the first set of columns before the '\|' describe the object:

	@@ -362,7 +362,7 @@ where the first set of columns before the '\|' describe the object:
	EM Object's event mask		EM Object's event mask
	EV Events raised on this object		EV Events raised on this object
	F Object flags		F Object flags
	S Object slow-work work item flags		S Object work item busy state mask (1:pending 2:running)

	and the second set of columns describe the object's cookie, if present:		and the second set of columns describe the object's cookie, if present:

	@@ -395,8 +395,8 @@ and the following paired letters:
	w Show objects that don't have pending writes		w Show objects that don't have pending writes
	R Show objects that have outstanding reads		R Show objects that have outstanding reads
	r Show objects that don't have outstanding reads		r Show objects that don't have outstanding reads
	S Show objects that have slow work queued		S Show objects that have work queued
	s Show objects that don't have slow work queued		s Show objects that don't have work queued

	If neither side of a letter pair is given, then both are implied. For example:		If neither side of a letter pair is given, then both are implied. For example:

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